UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 5 AIR AND RADIATION DIVISION 77 WEST JACKSON BOULEVARD CHICAGO, IL 60604-3590



### MAY 29Z01Z REPLY TOTHE ATTENTION OF:

MEMORANDUM _; SUBJECT: ComparisonofIllinois PowerPlantEmission Reductions to Reductions from Source-Specific Best Ava ilable RetrofitTechnology FROM: JohnSummerhays

# ~~~ AttainmentPlanning an&Maintenance Section TO: Files

At Title40 CodeofFederalRegulations 51.308(e)(2) (40 CFR51.308(e)(2)), EPA allows states to meetrequirements for best available retrofittechnology (BART) by mandating alternative measures in lieu ofmandating source-specific BART, so long as the alternative measures provide better visibility protection. Given the regional nature ofvisibility impainnent, an alternative that results in lower emissions ofsulfur dioxide (S02) andnitrogen oxides (NOx) will generally provide better visibility protection. Thus, in the absence ofdifferences inthe spatial distribution ofemissions, a modeling analysis is generally notnecessary to be able toconcludethat an alternative strategy with lower S02 andNOxemissionsprovides better visibilityprotection. In accordance with guidancepublished October 13,2006, at 71 FR60612, EPA stated that the presumptive BART levels given in the BART guidelines wouldbe a suitablebaseline against which to compare alternative strategies where the alternativehas been designed to meet a requirement otherthanBART. See 71 FR 60619; see also 40 CFR 51.308(e)(2)(i)(C). Accordingly, Illinois did notfully determine BARTona source-specific basis, and instead compared its alternat ive against a scenario inwhichBART-subjectunits metpresumptiveBART limits identified inEPA's BARTguidance. Nevertheless, to address a public comment, a further analysis was conductedto compare Illinois' strategy against a conservative estimate ofthe emissions ofBART ona source-specificbasis. Accordingto the RACT /BACT /LAERClearinghouse, the limits representingbest available control technology (BACT) inrecent permitshas averaged approximately 0.06 poundsper millionBritish Thermal Units (#/MMBTU) for S02 and also 0.06 #/MMBTUforNOx. These limits areimposed on newunits or units undergoingmajormodifications, which by definition sometimes have more latitude to be constructed with designs thatminimize emissions. Therefore, the emission limits representing BART, which bydefinition apply to relatively old existing units, are unlikely to belowerthanthe limits that would apply to new units and wouldin many cases be significantlyhigher.The following tables showthe emissions estimated for each unit ofeach power plantthat is regulated in Illinois' strategy for both the scenario implementing Illinois' strategy and the scenario implementing source-specific BART. Estimates for Illinois' strategy reflect the limits as of2017, which is the year by which BART or its equivalent must be implemented in Illinois. While Illinois' regulations, governing Ameren, Dynegy, and Midwest Generation, allow compliance on a company-wide basis, and thus allow compliance strategies that shift emissions from plantto plant, Illinois' regulations effectively limittotal emissions from each company. Since the primarypurpose ofthis analysis is to compare total emissions with Illinois' strategy against total emissions with application ofsource-specific BART, the use ofaverage allowable emission rates at each unit suffices for purposes here. These tables use datapresented in the technical support document for BART included inIllinois' submittal, except for use ofa BACT limit in place ofthe presumptive BART limits. (In addition, while Illinois' submittal computes reductions for Dominion Kincaid based on an S02 limit of0.18 #/MMBTU, as originally proposed for this facility, the tables below show revised results based onthe final permit limits of0.15 #/MMBTU.) These tables provide unit-by-unit details similarto the detailed computations presented inthe Illinois submittal. The following tables showthis information first for the Dynegy units (Table 1a), second for the Amerenunits (Table Ib, for units ofAmeren and its affiliates, as subjectto the Multi-Pollutant Standard in Illinois regulations), third for Midwest Generation (Table 1c), and fourth for City Water Light and Power and for Dominion Energy (Table 1d). Finally, Table 2 presents a summary ofthe results shown in Tables 1athrough 1d. As seen inTable 2, the Illinois strategy achieves somewhatmore reductions ofNOx emissions and substantially more reductions ofS02 emissions than the lowestplausible definition of BART. Table 2 indicates thatthis same result applies for the three companies that are subject either to the Multi-Pollutant Standard or to the Combined Pollutant Standard. Table 2 indicates thatthe reductions for Dominion Energy and City Water Light and Power are less than the reductions from the most controlling plausible definition ofBART. However, it is also possible thatthe reductions from these companies are fully equivalentto a more carefully analyzed estimate ofBART reductions. Furthermore, the purpose ofthe analysis here is to assess whether the collective set ofreductions mandated by Illinois across the state provides greater visibility protectionthan even a conservative estimate ofreductions that would be mandatedbyrequiring BART on a source-by-source basis to BART-subject sources. Table 2 shows that Illinois is mandating significantmore reductions than would be obtained evenunder the most conservative (mostcontrolling) plausible definition ofBART. Given the regional nature ofthe impacts of NOx and S02 emissions on visibility, and given the significantly greater emissionreductions provided in Illinois' strategy, this analysis indicates that Illinois' strategy satisfies the requirements for alternative strategies ofproviding greater visibilityprotectionthan application ofBART on a source-by-source basis to BART-subject sources.Table la. Comparison for Dynegy ofEmissions Reductions Under Illinois' Strategy Versus Emissions Reductions from Application of BACT Limits to BART Units
NOx 

### so, Dynegy Base Year BACT (0.06 Illinois Strategy Base Year BACT Illinois Strategy #/MMBTU) (0.10 (0.06 (0.19 #/MMBTU) #IMMBTU) #/MMBTU) Plant Unit MMM #I Tons Reduction Reduction #I Tons Reduction Reduction BTU MMBTU (tons) (tons) MMBTU (tons) (tons) Baldwin I 43,884 0.55 12,119 10,802 9,925 0.41 9,053 7,736 4,884 Baldwin 2 37,135 0.4 7,405 6,291 5,549 0.39 7,283 6,169 3,755 Baldwin 3 46,403 0.12 2,850 1,458 530 0.43 9,931 8,539 5,523 Havana 9 28,514 0.27 3,901

-- 2,475 0.9 12,185 -- 10,106 Hennepin I 4,684 0.32 760 -- 525 0.43 1,000 

### -- 555 Hennepin 2 17,575 0.33 2,862 

### -- 1,983 0.43 3,792 -- 2,122 Vermilion 1 5,311 0.37 986 -- 720 2.75 7,293 

### -- 6,788 Vermi1ion 2 6,741 0.37 1,231 -- 894 2.74 9,224 

### -- 8,584 Wood River 4 5,561 0.19 521 

### -- 243 0.55 1,536 

### -- 1,008 Wood River 5 17,611 0.22 1,903 -- 1,023 0.65 5,726 -- 4,053 Total: 18,551 23,867 22,444 47,378Table lb. Comparison for Ameren ofEmissions Reductions Under Illinois' Strategy Versus Emissions Reductions from Application of BACT Limits to BART Units
NOx 

## so, Ameren Base Year BACT (0.06 Illinois Strategy Base Year BACT Illinois Strategy #/MMBTU) (0.06 #/MMBTU) Plant Unit MMM #I Tons Reduction #I Reduction #I Tons Reduction #I Reduction BTU MMBTU (tons) MMBTU _(tons) MMBTU (tons.) MMBTU _(tons) Coffeen I 18,570 0.53 4,918 4,360 0.11 3,896 1.54 14,332 13,775 0.25 12,011 Coffeen 2 37,545 0.5 9,422 8,296 0.11 7,357 1.49 27,999 26,873 0.25 23,306 Duck Creek 1 22,635 0.47 5,328 4,649 0.11 4,083 0.97 11,026 10,347 0.25 8,197 ED 1 6,417 0.41 1,306 

### -- 0.11 953 3.55 11,399 

### -- 0.25 10,597 Edwards

ED 2 17,222 0.45 3,901 3,384 0.11 2,954 1.7 14,666 14,149 0.25 12,513 Edwards

ED 3 15,972 0.46 3,639 3,160 0.11 2,760 1.21 9,683 9,203 0.25 7,687 Edwards Hutsonville 5 3,161 0.57 897 -- 0.11 723 4.53 7,163 

### -- 0.25 6,768 Hutsonville 6 3,443 0.52 902 -- 0.11 712 4.53 7,791 -- 0.25 7,361 Joppa I 13,548 0.13 846 

### -- 0.11 131 0.51 3,441 

### -- 0.25 1,748 Joppa 2 16,258 0.13 1,048 -- 0.11 153 0.51 4,139 -- 0.25 2,107 Joppa 3 15,396 0.13 1030

-- 0.11 183 0.51 3,947 

### -- 0.25 2,023 Joppa 4 13,402 0.13 904 

### -- 0.11 167 0.52 3,488 

### -- 0.25 1,813 JOl'fl'l 5 15,094 0.12 939 -- 0.12 0 0.52 3,932 -- 0.25 2,045 Joppa 6 16,063 0.12 999 -- 0.12 0 0.52 4,182 -- 0.25 2,174 Meredosia 1 1,134 0.51 292 

### -- 0.51 0 5.02 2,844
-- 0.25 2,702 Meredosia 2 1,337 0.5 336 -- 0.5 0 5.02 3,356 

### -- 0.25 3,189 Meredosia 3 1,069 0.51 271 -- 0.51 0 5.04 2,694 -- 0.25 2,560 Meredosia 4 1,406 0.51 357 -- 0.51 0 5 3,518 -- 0.25 3,342 Meredosia 5 10,810 0.47 2,524 -- .047 0 2.34 12,639 

### -- 2.34 -9

Newton I 40,631 0.15 3,037
-- 0.15 0 0.45 9,046
-- 0.45 -96 Newton 2 38,533 0.11 2,215 

### -- 0.11 0 0.46 8,826 

### -- 0.46 -40 23,849 24,074 74,348 111,997Table !c. Comparison for Midwest Generation ofEmissions Reductions Under Illinois' Strategy Versus Emissions Reductions from Application ofBACT Limits to BART Units NOx SOz Midwest Generation Base Year BACT (0.06 Illinois Strategy Base Year BACT !llinois Strategy #/MMBTU) (0.11 (0.06 (0.11 #!MMBTU) #IMMBTU) #/MMBTU) Plant Unit MMM #I Tons Reduction Reduction #I Tons Reduction Reduction BTU MMBTU (tons) (tons) MMBTU (tons) (tons) Crawford 7 11,627 0.02 1,187 

### -- 547 0.54 3,142


### -- 2,503 Crawford 8 17,348 0.19 1,663 

### -- 709 0.51 4,453 -- 3,499

Fisk 19 14,650 034 2,463

-- 1,657 0.52 3,843 -- 3,037 Joliet 29 71 15,034 0.12 871 420 44 0.7 5,276 4,825 4,449 Joliet 29 72 13,824 0.12 816 401 56 0.7 4,828 4,413 4,068 Joliet 29 81 15,585 0.13 1,049 581 192 0.68 5,300 4,832 4,443 Joliet 29 82 15,403 0.14 1,073 611 226 0.68 5,260 4,798 4,413 Joliet 9 5 14,369 0.36 2,562 -- 1,772 0.63 4,559

-- 3,769 Powerton 51 20,936 0.73 7,594 6,966 6,442 0.42 4,444 3,816 3,293 Powerton 52 21,137 0.73 7,695 7,061 6,532 0.43 4,497 3,863 3,334 Powerton 61 18,293 0.66 5,995 5,446 4,989 0.43 3,964 3,415 2,958 Powerton 62 18,088 0.66 5,936 5,393 4,941 0.43 3,909 3,366 2,914 Waukegan 17 7,502 0.63 2,365

-- 1,953 0.44 1,642 -- 1,229 Waukegan 7 16,117 0.14 1,092 -- 206 0.47 3,754 -- 2,868 Waukegan 8 21,950 0.14 1,488 -- 280 0.49 5,385

-- 4,178 Will County I 9,398 0.85 4,000 -- 3,483 0.42 1,969 

### -- 1,452 Will County 2 8,293 0.8 3,310


### -- 2,854 0.39 1,617 -- I,161 Will County 3 15,559 0.17 1,300 -- 444 0.47 3,636 

### -- 2,780 Will County 4 27,585 0.15 2,009 1,181 491 0.47 6,462 5,634 4,945 Totals: 28,061 37,819 38,963 61,292 I

### Table ld. Comparison for Dominion Energy and City Water Light and Power ofEmissions Reductions Under Illinois' Strategy Versus Emissions Reductions from Application ofBACT Limits to BART Units

NOx 

### so, Dominion Energy, Base Year BACT (0.06 Illinois Strategy Base Year BACT Illinois Strategy City Water Light and Power #/MMBTU) (0.06 #/MMBTU) Plant Unit MMM #I Tons Reduction #I Reduction #I Tons Reduction #I Reduction BTU MMBTU (tons) MMBTU (tons) MMBTU (tons) MMBTU (tons) DE Kincaid 1 32,265 0.64 10,300 9,332 0.07 9,171 0.55 8,891 7,923 0.15 6,471 DE Kincaid 2 32,238 0.66 10,605 9,638 0.07 9,476 0.54 8,774 7,807 0.15 6,356 Totals: 18,970 16,874 15,730 12,827 CWLP 31 4,528 1.1 2,484 2,348 0.11 2,235 0.33 753 617 0.23 232 Dallman CWLP 32 4,787 1.11 2,654 2,510 0.11 2,391 0.35 835 691 0.23 284 Dallman CWLP 8 1,593 0.64 749 701 0 749 5.47 4,358 0 4,358 Lakeside Totals: 5,560 5,375 5,619 4,785Table 2. Summary ofthe comparison ofEmissions Reductions Under Illinois' Strategy Versus Emissions Reductions from Application of BACT Limits to BART Units

Company BART Total NOx Reductions S02 Reductions Units Units (tons/year) (tons/year) IL Plan Lowest IL Plan Lowest BART BART Ameren 5 24 24,074 23,849 111,997 74,349 Dynegy 3 10 23,867 18,551 47,378 22,444 MWG 9 19 37,819 28,061 61,292 38' 963 CWLP 3 3 5,375 5,560 4,875 5' 619 Dominion 2 2 16,874 18,970 12,827 15,730 Totals 22 58 108,009 94,991 238,369 157,105

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